1. Technical Field
The present invention pertains to a motion detection device, an electronic device, a motion detection method, and a program storage medium, and particularly relates to a motion detection device, an electronic device, a motion detection method, and a program storage medium that use a triaxial acceleration sensor to detect motion.
2. Related Art
Conventionally, a motion recognition device that recognizes motion accompanying operations intended by a user has been proposed (e.g., see Japanese Patent Application Laid-Open (JP-A) No. 2009-245176). In this motion recognition device, it is necessary to ensure that the device does not recognize as motion unintended vibration such as when the user boards a means of transportation, walks, runs, and so forth. Therefore, the motion recognition device described in JP-A No. 2009-245176 detects an axial direction in which there is the potential for the motion recognition device to be moving in accompaniment with an operation intended by the user on the basis of feature points of acceleration in each axial direction and detects and analyzes a feature amount of acceleration in that axial direction to thereby verify whether or not the motion in the detected axial direction is motion accompanying an operation intended by the user.
Further, a gravity axis determination device that determines one of three axes configuring a three-dimensional space to be the gravity axis has been proposed (e.g., see JP-A No. 2010-123040). This gravity axis determination device generates at least two axis acceleration signals, each of which indicates acceleration in directions of at least two axes of three axes, fetches each of the axis acceleration signals as at least two axis acceleration data strings, compares data values of the axis acceleration data strings in the same time slot, and determines any one of the three axes to be the gravity axis.
However, the technology described in JP-A No. 2009-245176 performs the complicated processing of detecting and analyzing the feature amount of acceleration in order to recognize motion, and the processing is cumbersome.
Further, the technology described in JP-A No. 2010-123040 determines the gravity axis in a case where the device is in a stationary state, but in a case in which motion such as shaking the device is applied as motion inputting (input operations by applying motion to the device), the acceleration data other than in the gravity axis also become greater, so the technology cannot accurately determine the gravity axis.